High Stiffness Tool For Expanding A Wellbore

ABSTRACT

A downhole tool may be used to enlarge and widen a wellbore. The downhole tool may include a reamer with a mandrel that includes a rib extending radially outward from a cylindrical body of the mandrel. The rib may define one or more grooves. A cutter block or other expandable member may be positioned adjacent the rib and may include one or more extensions that mate with the grooves. The rib and cutter block may be positioned within a slot of a housing. The housing may also include one or more grooves on a surface along the slot. The grooves along the slot and the grooves on rib may mate with extensions on opposing sides of the expandable member to define a path by which the expandable member moves between expanded and retracted positions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of, and priority to, U.S. PatentApplication Ser. No. 61/842,034, filed on Jul. 2, 2013 and entitled“HIGH STIFFNESS REAMER WITH INDEPENDENTLY EXPANDING CUTTING TOOLS” andto U.S. Patent Application Ser. No. 61/859,665, filed on Jul. 29, 2013and entitled “HIGH STIFFNESS REAMER WITH EXTENDED DEGRADATION TOOLS”.The foregoing applications are expressly incorporated herein by thisreference in their entireties.

BACKGROUND

In the drilling of oil and gas wells, a drill bit is coupled to a drillstring and rotated. Fluid may flow through the drill string and outnozzles in the drill bit. The fluid may cool the drill bit, flushcuttings away from the face of the drill bit, and carry the cuttings tothe surface of the wellbore.

Drilling may be used to create a wellbore having a particular diameter,but the diameter of a portion of the wellbore may be enlarged forvarious reasons. For example, the diameter of the wellbore may beenlarged to provide clearance for running casing, to obtain adequateannular space in the hole for cementing, to enlarge zones for gravelpack completion or cementing, and for other purposes.

Reamers (also known as underreamers) are used for enlarging the diameterof the wellbore. A reamer generally has two states, namely an inactiveor retracted state where the cutter blocks of the reamer are in aradially inward, retracted position and the reamer maintains a diametersmall enough to pass through the existing wellbore or casing strings,and an active, expanded, or deployed state where cutter blocks are in anoutward, radially extended position. In the active state, the cutterblocks can be used to enlarge the diameter of the wellbore.

SUMMARY

In accordance with an embodiment of the present disclosure, a reamer forwidening a wellbore may include a housing. The housing may have variousslots therein, and multiple expandable members may be located within theslots. A mandrel inside the housing may include ribs that also extendinto the slots.

In accordance with another embodiment of the present disclosure, amethod for widening a wellbore may include tripping a downhole tool intothe wellbore. The downhole tool may include a reamer with a mandrelcoupled to a cutter block. Fluid may be provided to the downhole toolthrough the mandrel, and the fluid may be used to expand the cutterblock. The cutter block may expand relative to the mandrel along a pathdefined by a rib that extends radially from the mandrel. The downholetool may then be rotated while the cutter block is expanded to widen thewellbore.

In another embodiment, a reamer is disclosed and includes a mandrelincluding a cylindrical body, a flow bore, and a rib. The rib may extendradially from the cylindrical body. A cylindrical housing may include aslot and the rib of the mandrel may be positioned in the slot. Anexpandable member in the slot and between the rib and a side of the slotmay be hydraulically actuated by a piston assembly. The piston assemblymay communicate with the flow bore of the mandrel to obtain thehydraulic force to move the expandable member to an expanded position. Abiasing member coupled to the cylindrical housing may mechanically drivethe expandable member to a retracted position.

This summary is provided to introduce a selection of concepts that arefurther described below in the detailed description. This summary is notintended to identify key or essential features of the claimed subjectmatter, nor is it intended to be used as an aid in limiting the scope ofthe claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a drilling system according to someembodiments of the present disclosure;

FIG. 2-1 is a perspective view of a reamer in an inactive or collapsedstate, according to some embodiments of the present disclosure;

FIG. 2-2 is a perspective view of the reamer of FIG. 2-1, with thereamer in an active or expanded state, according to some embodiments ofthe present disclosure;

FIG. 3 is a perspective view of a mandrel for use with the reamer ofFIGS. 2-1 and 2-2, according to some embodiments of the presentdisclosure;

FIG. 4 is a perspective view of another reamer for use with a reamer,according to some embodiments of the present disclosure;

FIG. 5 is a partial perspective, exploded view of a reamer for expandinga diameter of a wellbore, according to some embodiments of the presentdisclosure;

FIG. 6 is a partial cross-sectional view of the reamer of FIG. 5,according to some embodiments of the present disclosure; and

FIG. 7 is a partial perspective view of another reamer for expanding adiameter of a wellbore, according to some embodiments of the presentdisclosure.

DETAILED DESCRIPTION

In accordance with some aspects of the present disclosure, embodimentsherein relate to downhole tools. More particularly, embodimentsdisclosed herein may relate to downhole tools and bottomhole assemblies(“BHA”) that include an underreamer, which may also be referred to as areamer. An example BHA may include a reamer that may be used to expand adiameter of a wellbore along a full or partial length of the wellbore.In still other aspects, embodiments of the present disclosure may relateto high stiffness reamers including a mandrel guiding cutter blocks orother expandable members of the reamer as the expandable members movebetween retracted and expanded positions.

Referring now to FIG. 1, a schematic diagram is provided of an exampledownhole system 100 that may utilize wellbore enlargement systems,assemblies, devices, and methods in accordance with embodiments of thepresent disclosure. FIG. 1 shows an example wellbore 101 formed in aformation 102. A portion of the wellbore 101 may be cased or, as shownin FIG. 1, the wellbore 101 may be uncased or an openhole wellbore.

In the particular embodiment illustrated in FIG. 1, a BHA 103 may beprovided to facilitate enlargement of the wellbore 101, to cut into theformation 102, and the like. The BHA 103 may be connected to a drillstring 104. In FIG. 1, the drill string 104 is illustrated as extendingfrom the surface and having the BHA 103 suspended therefrom. The drillstring 104 may be composed of one or more tubular members. The tubularmembers of the drill string 104 may themselves have any number ofconfigurations. As an example, the drill string 104 may includesegmented/jointed drill pipe, slim drill pipe, wired drill pipe, coiledtubing, or the like.

The BHA 103 may include any number of components that may be used toperform one or more downhole operations. As an example, the BHA 103 mayinclude a drill bit 105, one or more stabilizers 106, a reamer 107,jars, drill collars, communication subs, measurement-while-drilling(MWD) tools, logging-while-drilling (LWD) tools, other components, orany combination of the foregoing. In some embodiments, the stabilizers106 may be used to maintain the BHA 103 in a centered position withinthe wellbore 101. In at least some embodiments, such centralization mayreduce or minimize vibrations within the BHA 103 and the drill string104 during a downhole operation, may center the drill bit 105, thereamer 107, or other components during a wellbore enlargement or otherdownhole operation, or provide other features.

The drill bit 105 may include a roller cone bit, a fixed cutter bit, apercussion hammer bit, a diamond impregnated bit, or some other drillbit configured for use in for drilling into the formation 102surrounding the wellbore 101 and extending the length of the wellbore101. In other embodiments, however, the drill bit 105 may have otherstructures or uses. For instance, the drill bit 105 may be a milling bitfor downhole milling operations (e.g., grinding up plugs or downholetools during a remedial operation). In still other embodiments, thedrill bit 105 may include another reamer for expanding the diameter ofthe wellbore 101.

In the particular embodiment shown in FIG. 1, a reamer 107 may beprovided. The reamer 107 may be used to expand a diameter of a portionof the wellbore 101. In at least some embodiments, the reamer 107 mayinclude expandable members that may be used to expand a diameter of thewellbore 101 beyond the diameter formed by the drill bit 105. In atleast some embodiments, the expandable members of the reamer 107 mayinclude cutter blocks that can be selectively expanded and retracted.For instance, when the BHA 103 is tripped/inserted into the wellbore101, the cutter blocks may be in a retracted position and have adiameter that is about equal to, or less than, a diameter of thewellbore 101. Upon reaching a desired depth, formation structure, or thelike, a signal may be sent from the surface (e.g., through wireless, mudpulse, fluid pressure, ball drop, string rotation, or other activationtechniques) to expand the cutter blocks so that they engage theformation 102 around the wellbore 101. As the BHA 103 is rotated andmoved axially within the wellbore, the expandable members may cutradially outward into the formation 102 and expand the diameter of thewellbore 101 along an axial length of the wellbore 101.

The particular components included on the BHA 103 may be varied in anynumber manners, and the BHA 103 may include additional or othercomponents 108 for use in any number of manners. By way of example,other components of the BHA 103, or which may be coupled to the BHA, mayinclude one or more LWD tools, one or more MWD tools, memory or datastorage devices, motors (e.g., mud motors, turbine motors, positivedisplacement motors, etc.), rotary steerable and directional drillingequipment (e.g., point-the-bit components, push-the-bit components,pad-in-bit components), casing-while-drilling or liner-while-drillingtools, disconnect subs or equipment, circulation subs, communicationequipment (e.g., pulsers, a signal processor, acoustic processors,wireless processors, signal boosters, fiber optic components, mud pulsetelemetry receivers/transmitters), cleaning nozzles, plugs, anchors,packers, isolation/sealing devices, liner hangers, other devices ortools, or some combination of the foregoing.

As shown in FIG. 1, a drilling rig 108 may be used to convey the drillstring 104 and BHA 103 into the wellbore 101. In an example embodiment,the drilling rig 108 may include a derrick and hoisting system 109, arotating system, a mud circulation system, or other components. Thederrick and hoisting system 109 may suspend the drill string 104, andthe drill string 104 may pass through a wellhead 110 and into thewellbore 101. In some embodiments, the drilling rig 108 or the derrickand hoisting system 109 may include a draw works, a fast line, a crownblock, drilling line, a traveling block and hook, a swivel, a deadline,or other components. An example rotating system may be used, forinstance, to rotate the drill string 104 and thereby also rotate one ormore components of the BHA 103. Example rotating systems may include atop drive, kelly, rotary table, or other components. Although thedownhole system 100 is shown in FIG. 1 as being on land, those of skillin the art will recognize that embodiments of the present disclosure arealso equally applicable to offshore and marine environments.

Turning now to FIGS. 2-1 and 2-2, partial perspective views of adownhole tool are provided. In particular, FIG. 2-1 illustrates thedownhole tool as a reamer 207 in a retracted, inactive, or collapsedstate while FIG. 2-2 illustrates the downhole tool as a reamer 207 in anexpanded or active state.

The reamer 207 may include any number of components or features thatallow it to be used in a downhole operation, such as an operation toexpand the diameter of a wellbore. For instance, the reamer 207 mayinclude a mandrel 211, a fluid inlet 212, a fluid outlet 213, one ormore pistons 214, one or more biasing member 215, one or more expandablemembers 216, other components, or any combination of the foregoing.

The reamer 207 may be designed to allow expansion of the one or moreexpandable members 216 as a result of increased pressure due to flowthrough the fluid inlet 212. Fluid entering the inlet 212 may flowthrough a bore in the mandrel 212 and out the fluid outlet 213. The flowand increased pressure may occur when the reamer 207 reaches a certaindepth within a wellbore, and may act on the one or more pistons 214 todrive the expandable members 216 radially outward and into engagementwith the formation around the wellbore. Rotation and axial movement ofthe reamer 207 may then allow the wellbore to be widened.

The reamer 207 may further include a body or housing 217 in which one ormore slots 218 may be formed. The housing 217 may be substantiallycylindrical, hexagonal, octagonal, or have some other regular orirregular geometric cross-sectional shape. The housing 217 may be formedof a single component, or multiple components may collectively make upthe housing 217.

The housing 217 may be hollow or tubular, and the slots 218 may, in someembodiments, extend through a thickness of a wall of the housing 217. Insome embodiments, the slots 218 may be aligned with the expandablemembers 216. As a result, when the fluid flow increases pressure in themandrel 211 and the pistons 214, the pistons 214 may move (e.g., in anuphole direction) and cause the expandable members 216 to move radiallyoutward through the slots 218. When the fluid pressure is reduced in themandrel 211, the pistons 214 may move in an opposite direction (e.g., ina downhole direction) and allow the expandable members 216 to moveradially inward through the slots 218, and toward a compressed orinactive position.

In some embodiments, the pistons 214 (or a single piston) may be locatedaround the mandrel 211 and proximate the fluid outlet 213. The housing217 may be located axially between the pistons 214 and the one or morebiasing members 215. As discussed in greater detail with respect to FIG.6, the biasing members 215 (or a single biasing member) may bepositioned around the mandrel and expansion of the expandable members216 may overcome the bias of the biasing members 215 (e.g., bycompressing the springs or other biasing members 215). As the fluidstops flowing, or as the fluid flow decreases, the biasing members 215may cause the expandable members 216 to move toward the inactive orretracted position. For instance, the biasing members 216 may cause theexpandable members 216 (or the housing 217) to move toward the pistons214, which may potentially also move the pistons 214.

As discussed herein, as fluid flows from the fluid inlet 212 and throughthe reamer 207 (e.g., toward or through the fluid outlet 213), theexpandable members 216 may be actuated from collapsed, inactive, orretracted positions to expanded or active positions. In someembodiments, the collapsed, inactive, or retracted position of theexpandable members 216 (or the collapsed, inactive, or retracted stateof the reamer 207) may be defined as when the expandable members 216 aresubstantially positioned within the housing 217. The reamer 207 maywiden the wellbore by cutting, shearing, impacting, or otherwisedegrading formation material adjacent the expandable members 216 whenthe reamer 207 is in the expanded or active state. In some embodiments,the expandable members 216 may move at equal rates or distances whenexpanded or retracted. In other embodiments, however, the expandablemembers 216 may move at different rates or distances. For instance, eachof the pistons 214 or biasing members 215 may be differently configuredto operate at a different time or rate. When each expandable member 216is expanded, each expandable member 216 may contribute to expanding andwidening the wellbore.

In some embodiments, the housing 217 and/or the mandrel 211 may be usedin expanding and/or retracting the expandable members 216. As seen inFIGS. 2-1 and 2-2, for instance, the housing 217 may include one or moregrooves 219 that mate with one or more ridges, splines, or otherextensions 220 of the expandable members 216. In particular, theextensions 220 may be formed in opposing lateral side surfaces of theexpandable members 216, and corresponding grooves 219 may be formed onthe sides of the housing 217 on each side of the expandable members 216.

The grooves 219 and extensions 220 may, in some embodiments, be formedat an angle relative to the longitudinal axis of the reamer 207. Forinstance, the grooves 219 and extensions 220 may be formed at an anglethat is between 5° and 90° from the longitudinal axis of the reamer 207.More particularly, the angle may be within a range having lower and/orupper limits including any of 5°, 10°, 15°, 17°, 20°, 23°, 25°, 30°,40°, 50°, 60°, 75°, 80°, 85°, 90°, and any values therebetween. Forinstance, the angle may be less than 40°, greater than 15°, between 15°and 30°, between 17° and 23°, between 20° and 60°, or between 75° and90°. In one example, the angle may be 90°, which may facilitate movingthe expandable members 216 in a radial direction that is perpendicularto the mandrel 211 and/or the longitudinal axis of the reamer 207. Inanother example, such as where the angle is less than 90°, theexpandable members 216 may expand and retract by moving bothlongitudinally and axially along a path that is non-parallel andnon-perpendicular relative to the mandrel 211, the housing 217, or thelongitudinal axis.

In the same or other embodiments, the mandrel 211 may also includegrooves 221 that mate with the extensions 220 of the expandable members216 (e.g., extensions 220 on an opposite side of the expandable members216 as compared to the extensions 220 that mate with the grooves 219).In some embodiments, the grooves 221 may be angled relative to thelongitudinal axis of the reamer 207. For instance, the grooves 221 maybe at a same or different angle than the grooves 219. In someembodiments, the extensions 210 on opposing sides of the expandablemembers 216 may be at the same angle, while in other embodiments theextensions 220 on opposing sides of the expandable members 216 may beoriented at different angles.

As discussed in more detail herein, one or more ribs 222 may be coupledto, or integrally formed with, the mandrel 211. The ribs 222 may includewings, extensions, appendages, or other features that extend radiallyoutward from a central body or tube of the mandrel 211. The ribs 222 mayalign with the slots 218 and the expandable members 216. For instance,each rib 222 may be located along a side of one expandable member 216.The grooves 221 in the rib 222 may mate with the extensions 220, so thatas the expandable members 216 expand or retract a corresponding one ofthe ribs 222 may engage the extensions 220 and guide the expandablemembers 216. In other embodiments, the ribs 222 may be formed orpositioned on both sides of the expandable members 216. Further, whilethe illustrated embodiment may include grooves 219, 221 on the housing217 and ribs 222, respectively, in other embodiments, the grooves 219,221 may be replaced with extensions and the extensions 220 on theexpandable members 216 may be replaced with grooves.

The ribs 222 may extend radially from a cylindrical or other similarlyshaped body of the mandrel 211, and may assist in holding the expandablemembers 216 in an expanded position and/or in guiding the expandablemembers 216 between expanded and retracted positions. In someembodiments, moment forces on the expandable members 216 may increase asthe radial distance between the expandable members 216 and alongitudinal axis of the reamer 207 increases. By fixing the ribs 222 tothe mandrel 211, additional support for the expandable members 216 maybe provided at or proximate the outer surface of the housing 207.

In particular, the ribs 222 may extend at least partially through theslots 218 in some embodiments. For instance, the ribs 222 may extendradially outward from the body of the mandrel 211 and to a position thatis radially adjacent the housing 217. In some embodiments, the ribs 222may extend radially outward to be about aligned with the outer surfaceof the housing 217. As will be appreciated by a person having ordinaryskill in the art in view of the present disclosure, when the ribs 222have a radius that is greater than a radius of the opening or borewithin the housing 217, the housing 217 may not be able to slide overthe mandrel 211 and the ribs 222. In such an embodiment, the housing 217may be formed of multiple segments that can be positioned around themandrel 211 and secured together using welding, clamps, clasps,mechanical fasteners, or other connectors. In other embodiments, theribs 222 may not be integral with the mandrel 211, and the ribs 222 maybe coupled to the mandrel 211 after the mandrel 211 is installed withinthe housing 217. In some embodiments, the mandrel 211 may hold the fluidpressure within the reamer 207 and the housing 217 may not befluid-tight.

The reamer 207 may include any number of different configurations forthe mandrel 211, ribs 222, housing 217, expandable members 216, and thelike. For instance, the reamer 207 may include three (3) expandablemembers 216. As a result, there may also be three (3) slots 218 in thehousing 217, and three (3) ribs 222. In other embodiments there may besix (6) ribs 222. The number of expandable members 216 may, however, bevaried, and in other embodiments there may be one (1), two (2), four(4), five (5), six (6), eight (8), ten (10), or more expandable members216.

FIGS. 3 and 4 illustrate example mandrels 311, 411 in additional detail.The mandrels 311, 411 may be used in a downhole tool that includesexpandable members. More particularly, the mandrels 311, 411 may be usedto provide additional structural integrity or higher stiffness forexpandable members such as cutter blocks of a reamer.

More particularly, FIG. 3 is a perspective view of a mandrel 311 for usein a reamer or other downhole tool. The mandrel 311 may include a body323 and a plurality of ribs 322 extending radially from the body 323. Insome embodiments, the body 323 may be substantially cylindrical, and thecross-sectional shape of the body 323 may be substantially constant. Inother embodiments, however, the cross-sectional shape of the body 323may vary. For instance, FIG. 3 illustrates a body 323 that changes insize. More particularly, the distal end portions may have a largercross-sectional size relative to an intermediate portion 324. In atleast the illustrated embodiment, the ribs 322 may extend radiallyoutward from the intermediate portion 324. Grooves 321 in the ribs 322may extend along a full radial length of the ribs 322. As a result,cutter blocks or other expandable members that retract into a reamer orother downhole tool may retract to a position that is proximate thereduced diameter of the intermediate portion 324. By retracting furtherinto the downhole tool, corresponding cutter blocks or other expandablemembers may have an increased size allowing for a larger range ofexpansion and a greater ratio between the expanded radius and theretracted radius of the downhole tool. For instance, in someembodiments, the ratio of a downhole tool in expanded state relative tothe retracted state may be between 1.15:1 and 1.75:1. In otherembodiments, the ratio may be less than 1.15:1 or greater than 1.75:1.When the mandrel 311 thus includes a plurality of ribs 322 that extendradially outward from the body 323 and radially into the body 323 of themandrel 311, a corresponding reamer may expand a wellbore to a largerdiameter due to an increased range of motion that the cutter blocks orother expandable members can move through.

In FIG. 3, the mandrel 311 may include three (3) ribs 322 extendingradially outward from the body 322. The three (3) ribs 322 may be spacedcircumferentially around the mandrel 311 at 120° increments, such thatthere may be substantially equal spacing between the three ribs 322. Inother embodiments, however, a mandrel may include or otherwise becoupled to more or fewer than three (3) ribs. FIG. 4, for instance, is aperspective view of a mandrel 411 for a reamer or other downhole tool,in which a body 423 is coupled to two (2) ribs 422. The two (2) ribs 422may be circumferentially offset around the mandrel at 180° incrementsrelative to a longitudinal axis of the mandrel 411. With the mandrel 411including two (2) ribs 422, a corresponding reamer may be able to expanda wellbore to a larger diameter than may be possible for a similarlysized configuration that includes a larger number of ribs on themandrel. When the reamer is in a retracted state, a larger number ofribs 422 may be limited in the positions they could occupy in or alongthe body 423 of the mandrel 411 due to interference between one another.This could limit the size of a reamer that could fit inside a finitespace defined by the diameter of a wellbore, or the size of anexpandable member or cutter block that could fit inside a finite spacedefined by a housing of a reamer.

FIG. 5 is a partial perspective view of a reamer 507 according to stillanother embodiment of the present disclosure. The reamer 507 may includea plurality of expandable members 516, a plurality of housings 517, anda mandrel 511. The mandrel 511 may include, or be coupled to, aplurality of ribs 522 cooperating with corresponding slots 518 in acorresponding one of the plurality of housings 517. A cutter block orother expandable member 516 and a rib 522 may be positioned in eachcorresponding slot 518.

The expandable members 516 may include extensions 520 on one or bothsides thereof. One side of the expandable members 516 (and thus theextensions 520 on that side) may be adjacent the housing 517, while theother side of the expandable members (and thus the extensions 520 onthat side) may be adjacent a corresponding rib 522. The housing 517 mayinclude grooves 519 on a side adjacent the slot 518 and a correspondingexpandable member 516. The grooves 519 may mate with the extensions 520on the expandable member 516. The rib 522 may include one or moregrooves 521 on a side adjacent the corresponding expandable member 516such that the extensions 520 on the expandable member 516 can slidealong the grooves 521 in the rib 522.

Each expandable member 516 may be positioned between a corresponding rib522 and a housing 517. In other words, the grooves 521 on the rib 522and the slot 518 may function as tracks on which the extensions 520 onthe expandable member 516 may slide when actuated. The orientation ofthe expandable member 516 with respect to a mating rib 522 and matinghousing 517 may allow the expandable member 516 to be in contact withboth the housing 517 and the rib 522, thereby distributing the stressassociated with the reaming or other downhole operation over the lengthof the expandable member 516, and along the mandrel 511 and the housing517. Each of the plurality of expandable members 516 may be similarlyoriented.

FIG. 6 is a partial cross-sectional view of a reamer 607 in accordancewith another embodiment of the present disclosure. The reamer 607 mayinclude a mandrel 611, a fluid inlet 612, and a fluid outlet 613. Themandrel 611 may define a flow bore 624 having a substantiallycylindrical shape, and which optionally extends between the fluid inlet612 and the fluid outlet 613. A fluid may pass through the flow bore624. The mandrel 611 may further include a plurality of ribs 622 thatextend radially outward from a longitudinal axis of the mandrel 611.

In some embodiments, the reamer 607 may further include a plurality ofpiston assemblies 614 and at least one biasing member 615 (e.g., acompression spring). The reamer 607 may also include a plurality ofhousings 617, each of which may include or define at least one slot 618.The plurality of piston assemblies 614 may be located radially aroundthe mandrel 611 and/or proximate the fluid outlet 613. The plurality ofhousings 617 and/or the at least one biasing member 615 may also belocated radially around the mandrel 611 (e.g., a reduced cross-sectionalarea portion or body of the mandrel 611). The plurality of housings 617may be located longitudinally between the least one biasing member 615and the plurality of piston assemblies 614. In some embodiments, theplurality of piston assemblies 614 may be coupled to the plurality ofhousings 617 by a plurality of connectors 625.

In at least some embodiments, the plurality of piston assemblies 614 maybe in fluid communication with the flow bore 624. For instance, aplurality of fluid channels 626 that extend radially between the flowbore 624 and the plurality of piston assemblies 614 may fluidly couplethe plurality of piston assemblies 614 to the flow bore 624. As aresult, when a fluid flows from the fluid inlet 612 toward the fluidoutlet 613, some of the fluid may enter the plurality of fluid channels626. This flow of fluid in the fluid channels 626 may actuate theplurality of piston assemblies 614. Due to the connector 625 connectingthe plurality of piston assemblies 614 to the plurality of housings 617,the plurality of housings 617 may then move. When the plurality ofhousings 617 moves axially (e.g., in an uphole direction toward thefluid inlet 612 and the at least one biasing member 615) with respect tothe mandrel 611, the expandable members 616 may be forced to move to anexpanded position. As the plurality of housings 617 are actuated towardthe at least one biasing member 615, the at least one biasing member 615may be compressed.

As the fluid stops or slows through the flow bore 624 and the pluralityof fluid channels 626, the at least one biasing member 615 may actuatethe plurality of housings 617 and move the plurality of housings 617toward the plurality of piston assemblies 614 (e.g., in a downholedirection). When the plurality of housings 617 are actuated toward theplurality of piston assemblies 614, the expandable members 616 may bede-actuated to a collapsed position. Thus, in the embodiment shown inFIG. 6, the reamer 607 may be actuated and de-actuated by moving theplurality of housings 617 relative to the mandrel 611. In otherembodiments, however, the reamer 607 may activated and de-actuated bymoving the expandable members 616 relative to the mandrel 611 and whilethe plurality of housings 617 remain stationary relative to the mandrel611.

FIG. 7 is a perspective view of a reamer 707 according to still otherembodiments of the present disclosure. The reamer 707 may include amandrel 711, a plurality of housings 717, a plurality of expandablemembers 716, and a plurality of piston assemblies within a pistonsection 714. The mandrel 711 may include a substantially cylindricalshaped body, and a plurality of ribs 722 that extend radially outwardtherefrom. Together, the plurality of housings 717 may form asubstantially cylindrical shape around a portion of the mandrel 711. Insome embodiments, one of the plurality of housings 717 may include ordefine a slot 718 in which a rib 722 and an expandable member 716 arelocated. The expandable member 716 may be positioned between a side ofthe rib 722 and a side of the slot 718. A particular piston assembly(see FIG. 6) of the piston section 714 may correspond to each expandablemember 716 or housing 717. For instance, one of the plurality ofhousings 717 may be coupled to a corresponding piston assembly using aconnector (e.g., connector 625 of FIG. 6). Such a connector may allowfor axial movement of a housing 717 but restrict rotational or radialmovement of individual housings of the plurality of housings 717.Connectors may also couple different housings 717 together, in additionto coupling corresponding piston assemblies together. In someembodiments, the connector also may ensure that one piston assembly isaligned with a corresponding housing 617, as well as ensure that anotherpiston assembly is aligned with its corresponding housing 617. This mayallow each expansion region 727 of the reamer 707 to move independentlyof one another in an axial direction. An expansion region may be definedas an expandable member 716 along with a corresponding one of thehousings 717 and piston assemblies 714.

The plurality of housings 717 may be coupled together in any number ofmanners. For instance, mechanical fasteners, slot-and-tab, and otherconnectors may be used. By way of illustration, in some embodiments,each of the plurality of housings 717 may include a side with a slotthat runs parallel to the longitudinal axis of the mandrel 711, and aside with a tab or ridge, such that a ridge on one of the plurality ofhousings 717 may fit into a slot on an adjacent one of the plurality ofhousings 717. Each of the plurality of housings 717 may be similarlyfastened to their respective adjacent housings 717. Each of theplurality of piston assemblies of the piston section 714 may besimilarly fastened to their respective adjacent piston assemblies.

Using slots and ridges to join adjacent components may allow componentsto move in an axial direction, as may be allowed by using theconnectors, while potentially restricting or preventing relativerotational or radial movement between adjoining components. In someembodiments, for instance, one piston assembly may exert an axial forceon a corresponding housing, which may actuate an expandable member to anexpanded or active position. Though each additional expandable membermay be likewise actuated to an expanded or active position, each of theexpandable members may be in slightly different spatial orientations dueto inconsistencies in geometry resulting from wear or manufacturingerror.

In the description herein, various relational terms are provided tofacilitate an understanding of various aspects of some embodiments ofthe present disclosure. Relational terms such as “bottom,” “below,”“top,” “above,” “back,” “front,” “left”, “right”, “rear”, “forward”,“up”, “down”, “horizontal”, “vertical”, “clockwise”, “counterclockwise,”“upper”, “lower”, and the like, may be used to describe variouscomponents, including their operation and/or illustrated positionrelative to one or more other components. Relational terms do notindicate a particular orientation for each embodiment within the scopeof the description or claims. For example, a component of a bottomholeassembly that is described as “below” another component may be furtherfrom the surface while within a vertical wellbore, but may have adifferent orientation during assembly, when removed from the wellbore,or in a deviated borehole. Accordingly, relational descriptions areintended solely for convenience in facilitating reference to variouscomponents, but such relational aspects may be reversed, flipped,rotated, moved in space, placed in a diagonal orientation or position,placed horizontally or vertically, or similarly modified. Certaindescriptions or designations of components as “first,” “second,”“third,” and the like may also be used to differentiate between similarcomponents. Such language is not intended to limit a component to asingular designation. As such, a component referenced in thespecification as the “first” component may be the same or different thana component that is referenced in the claims as a “first” component.

Furthermore, while the description or claims may refer to “anadditional” or “other” element, feature, aspect, component, or the like,it does not preclude there being a single element, or more than one, ofthe additional element. Where the claims or description refer to “a” or“an” element, such reference is not be construed that there is just oneof that element, but is instead to be inclusive of other components andunderstood as “at least one” of the element. It is to be understood thatwhere the specification states that a component, feature, structure,function, or characteristic “may,” “might,” “can,” or “could” beincluded, that particular component, feature, structure, orcharacteristic is provided in some embodiments, but is optional forother embodiments of the present disclosure. The terms “couple,”“coupled,” “connect,” “connection,” “connected,” “in connection with,”and “connecting” refer to “in direct connection with,” or “in connectionwith via one or more intermediate elements or members.” Components thatare “integral” or “integrally” formed include components made from thesame piece of material, or sets of materials, such as by being commonlymolded or cast from the same material, or commonly machined from thesame piece of material stock. Components that are “integral” should alsobe understood to be “coupled” together.

Although various example embodiments have been described in detailherein, those skilled in the art will readily appreciate in view of thepresent disclosure that many modifications are possible in the exampleembodiments without materially departing from the present disclosure.Accordingly, any such modifications are intended to be included in thescope of this disclosure. Likewise, while the disclosure herein containsmany specifics, these specifics should not be construed as limiting thescope of the disclosure or of any of the appended claims, but merely asproviding information pertinent to one or more specific embodiments thatmay fall within the scope of the disclosure and the appended claims. Anydescribed features from the various embodiments disclosed may beemployed in combination.

A person having ordinary skill in the art should realize in view of thepresent disclosure that equivalent constructions do not depart from thespirit and scope of the present disclosure, and that various changes,substitutions, and alterations may be made to embodiments disclosedherein without departing from the spirit and scope of the presentdisclosure. Equivalent constructions, including functional“means-plus-function” clauses are intended to cover the structuresdescribed herein as performing the recited function, including bothstructural equivalents that operate in the same manner, and equivalentstructures that provide the same function. It is the express intentionof the applicant not to invoke means-plus-function or other functionalclaiming for any claim except for those in which the words ‘means for’appear together with an associated function. Each addition, deletion,and modification to the embodiments that falls within the meaning andscope of the claims is to be embraced by the claims.

While embodiments disclosed herein may be used in oil, gas, or otherhydrocarbon exploration or production environments, such environmentsare merely illustrative. Systems, tools, assemblies, reamers, wellboreexpansion systems, methods, and other components of the presentdisclosure, or which would be appreciated in view of the disclosureherein, may be used in other applications and environments. In otherembodiments, cutting inserts, cutting tools, milling tools, methods ofmilling, methods of cutting, methods of initiating a cutout, or otherembodiments discussed herein, or which would be appreciated in view ofthe disclosure herein, may be used outside of a downhole environment,including in connection with other systems, including within automotive,aquatic, aerospace, hydroelectric, manufacturing, other industries, oreven in other downhole environments. The terms “well,” “wellbore,”“borehole,” and the like are therefore also not intended to limitembodiments of the present disclosure to a particular industry. Awellbore or borehole may, for instance, be used for oil and gasproduction and exploration, water production and exploration, mining,utility line placement, or myriad other applications.

Certain embodiments and features may have been described using a set ofnumerical values that may provide lower and upper limits. It should beappreciated that ranges including the combination of any two values arecontemplated unless otherwise indicated, and that a particular value maybe defined by a range having the same lower and upper limit. Anynumerical value is “about” or “approximately” the indicated value, andtakes into account experimental error and variations that would beexpected by a person having ordinary skill in the art. Any numbers,percentages, ratios, measurements, or other values stated herein aretherefore intended to include the stated value as well as other valuesthat are about or approximately the stated value, as would beappreciated by one of ordinary skill in the art encompassed byembodiments of the present disclosure. A stated value should thereforebe interpreted broadly enough to encompass values that are at leastclose enough to the stated value to perform a desired function orachieve a desired result. The stated values include at leastexperimental error and variations that would be expected by a personhaving ordinary skill in the art, as well as the variation to beexpected in a suitable manufacturing or production process. A value thatis about or approximately the stated value and is therefore encompassedby the stated value may further include values that are within 5%,within 1%, within 0.1%, or within 0.01% of a stated value.

The abstract included with this disclosure is provided to allow thereader to quickly ascertain the general nature of some embodiments ofthe present disclosure. It is submitted with the understanding that itwill not be used to interpret or limit the scope or meaning of theclaims.

What is claimed is:
 1. A reamer for widening a wellbore, comprising: ahousing defining a plurality of slots; a plurality of expandable memberspositioned within the plurality of slots; and a mandrel within thehousing, the mandrel including a plurality of ribs extending into theplurality of slots.
 2. The reamer of claim 1, the plurality ofexpandable members being configured to expand and retract within theplurality of slots.
 3. The reamer of claim 1, the plurality ofexpandable members each including at least one extension configured tomate with a corresponding groove on at least one of the housing or theplurality of ribs.
 4. The reamer of claim 3, the housing and theplurality of ribs each including at least one groove configured to matewith extensions of the plurality of expandable members.
 5. The reamer ofclaim 4, the plurality of expandable members being positioned to have afirst side adjacent at least one groove of the housing, and a secondside adjacent at least one groove of the plurality of ribs.
 6. Thereamer of claim 1, the housing including a plurality of housingsconfigured to move longitudinally relative to the mandrel.
 7. The reamerof claim 1, further comprising: at least one piston configured to expandthe plurality of expandable members.
 8. The reamer of claim 1, furthercomprising: at least one biasing member configured to return theplurality of expandable members toward a retracted position.
 9. A methodfor widening a wellbore, comprising: tripping a downhole tool into awellbore, the downhole tool including a reamer having a mandrel coupledto at least one cutter block; providing fluid to the downhole toolthrough the mandrel; using the fluid to expand the at least one cutterblock relative to the mandrel, and along a path defined by a ribextending radially from the mandrel; and rotating the downhole toolwhile the at least one cutter block is expanded, and thereby wideningthe wellbore.
 10. The method of claim 9, wherein using the fluid toexpand the at least one cutter block relative to the mandrel includesusing a piston to expand the at least one cutter block.
 11. The methodof claim 9, wherein the path is defined by one or more mating groovesand extensions of the rib and the at least one cutter block.
 12. Themethod of claim 11, wherein the one or more mating grooves andextensions are oriented at an angle relative to a longitudinal axis ofthe mandrel.
 13. The method of claim 9, wherein the reamer includes ahousing defining at least one slot, the at least one cutter block andthe rib being positioned in the at least one slot.
 14. The method ofclaim 13, wherein the at least one cutter block includes at least oneextension on a first side of the at least one cutter block and at leastone extension on a second side of the at least one cutter block, thefirst and second sides of the at least one cutter block being opposingsides, and wherein the rib includes at least one groove mating with theat least one extension on the first side, and wherein the housingincludes at least one groove mating with the at least one extension onthe second side.
 15. The method of claim 9, wherein using the fluid toexpand the at least one cutter block includes expanding the at least onecutter block radially and longitudinally relative to the mandrel. 16.The method of claim 15, wherein in an expanded position, the at leastone cutter block is engaged with the fin of the mandrel.
 17. The methodof claim 9, wherein using the fluid to expand the at least one cutterblock includes moving a housing of the reamer axially to expand the atleast one cutter block.
 18. A reamer, comprising: a mandrel including asubstantially cylindrical body, a flow bore, and a rib extendingradially from the substantially cylindrical body; a housing defining asubstantially cylindrical shape with a slot, the rib of the mandrelbeing positioned in the slot; an expandable member in the slot betweenthe rib and a side of the slot; a piston assembly in communication withthe flow bore of the mandrel and configured to hydraulically actuate theexpandable member from a retracted position to an expanded position; anda biasing member coupled to the housing and configured to mechanicallydrive the expandable member from the expanded position toward theretracted position.
 19. The reamer of claim 18, the rib being integrallyformed in the mandrel.
 20. The reamer of claim 18, the housing, rib, andexpandable member defining a plurality of mating grooves and extensionsthat define a path that is angled relative to a longitudinal axis of themandrel and along which the expandable member moves between theretracted and expanded positions.